Movie 1

The effect of histamine on atrial contraction in an in situ perfused turtle heart. Histamine (100 nmol kg-1 bolus) was injected into the perfusate line at the start of the recording period. Before histamine reaches the heart, the atria clearly distend during diastole. Once histamine reaches the heart, the diastolic filling is curtailed as the atria become tonically constricted, which reduces cardiac output.

Contraction of atrial smooth muscle reduces cardiac output in perfused turtle hearts

William Joyce, Michael Axelsson, and Tobias Wang

Journal of Experimental Biology 2019. 222:None-None; doi: 10.1242/jeb.199828